The present invention relates to a extremely compact EPA certifiable gasoline engine driven electrical generating system (a “genset”) and more particularly, to a compartment contained genset that may be completely single side serviced in situ, having access to all the routine maintenance components and access points.
Specialty motorcoaches, like intercity traveling medical facilities, make the most out of the least amount of space. To stay competitive in today's marketplace motorcoaches use multiple slide out side and rear compartments. While maximizing and increasing interior space these slide outs do restrict the usable space below the motorcoach's floor deck. The current industry standard size for a genset compartment (for a genset and it's compartment housing, excluding the muffler) is approximately 34 inches long, 25 inches deep and 26 inches high. This movement toward less usable space below the motorcoach's floor deck has occurred at the same time as motorcoach retailers have seen an increase in the secondary electrical demands of the motorcoach.
Generating more electrical power in a motorcoach can be accomplished two ways. One way is to operate the genset at higher running speeds (which results in an undesired increase in noise, heat output, vibration, mechanical wear and servicing.) Another way is to use larger engines and generators. These brutes can output more power running at lower speeds, but because of their physical volume, require larger housing compartments. Enlarging a genset compartment upwards or downwards necessitates a protuberance in the motorcoach floor or a reduction in the motorcoaches's ground clearance. Unfortunately, for aesthetical reasons motorcoach designers seek smooth floors and a straight visible door line about the motorcoach.
The longer gensets are too large for the existing available spaces along the length of the motorcoach with the slide outs. Since the available space for genset compartments is limited, if a larger genset is installed it will cramp the compartment, hinder access to maintenance points, and result in a higher compartment ambient air temperature which will be forced through the generator housing interior causing premature generator failure. Add to this conundrum, the need for additional mechanical equipment required to pass the updated EPA NOX emission and other regulations, and the problem magnifies. Thus, the need for diminutive, high electrical output gensets evolved.
The development of space restricted gensets has an additional problem to overcome. As with all partially enclosed heat generating engines, heat buildup, especially from the exhaust components is a problem. Generator coils and windings have narrow operating temperatures and the cooling air circulated through them must also be relatively free of excess airborne particulate. The gasoline engines themselves are prone to overheating in the enclosed compartments and must possess efficient heat removal capacity. To complicate matters, side access doors often must remain closed when the genset is operating, further restricting air flow and containing residual heat in the compartment.
Henceforth, a cool running, quiet, low speed, long life, small genset that can be serviced in situ and capable of meeting current EPA standards while producing a large power output, would fulfill a long felt need in the motorcoach industry. This new invention utilizes and combines known and new technologies in a unique and novel configuration to overcome the aforementioned problems and accomplish this.